After a burglar smashed one of the larger-than-life Tiffany windows ringing Boston’s Church of the Covenant last fall, the first call was to the police, the second to Roberto Rosa, a Needham stained-glass specialist. At work on the State House nearby, Rosa rushed over, discovering a heap of luminescent shards — some as small as a fingernail — beneath a jagged depiction of the disciple Dorcas.

The task was daunting even for Rosa, whose Serpentino Stained & Leaded Glass
studio counts many of the region’s most vaunted institutions as clients. There is stained glass, and then there is Tiffany’s signature drapery glass — uniquely rippled and layered, rich in texture as well as color, from the firing ovens of one of America’s most celebrated decorative artists.

The problem? Louis Comfort Tiffany died nearly 80 years ago. And though the New York archive that has preserved unused materials from his studio promised to provide rare replacement glass to the church for free, nothing in its collection matched its needs. That setback was part of what became a remarkable odyssey for the small church, member Charlene James said, culminating in the window’s restoration.

“This is Dorcas, who’s been away for a year,” said James, the church’s resident window expert, standing beneath the soaring installation moments before a rededication service Sunday. “Doesn’t she look fabulous?”

The Church of the Covenant, at Newbury and Berkeley streets, houses what scholars consider the largest, most complex, and most intact Tiffany interior in America, a hidden gem that even many Bostonians do not know about.

In 1894, a minister, Mayflower descendant, and noted aesthete named Edward Lord Clark
persuaded the membership of what was then called Central Congregational Church to completely redecorate their nearly 30-year-old building, hiring Tiffany not just for the windows but for everything: paint colors, woodwork, and all.

By the time the congregation nudged Clark aside a few years later, with bills mounting, Tiffany had replaced 42 of the 47 windows with his own creations — including the one with Dorcas, and 19 others portraying biblical figures — and hung above the transept a six-by-12-foot sculpture-laden chandelier that had been a star of Chicago’s 1893 Columbian Exposition and is today considered the mother of all Tiffany lamps.

All of which conveys the appearance of wealth, but inspection reveals crumbling masonry, peeling floor tiles, and windows dimmed by a century of silt trapped between once-resplendent stained-glass layers.

“We aren’t rich enough to keep up the building,” said Holly Humphreys of Reading, a member of the church council.

What they are is a liberal, mainline Protestant church (aligned with both the Presbyterian Church and United Church of Christ) with 125 dedicated members drawn from across the region. Social justice figures heavily in the church’s mission — the Women’s Lunch Place, a day shelter, rents the basement — making the window of Dorcas, who was devoted to poor women and is rarely represented in church art, especially meaningful.

Last November, the church was raising seed money for a 20-year master plan that had identified millions of dollars in structural and cosmetic needs when someone scampered up some exterior scaffolding.
The thief, entering at night, succeeded in stealing just a couple of computers from an art gallery that rents space from the church — and shattering the bottom third of the Dorcas window, ruining its structural integrity as well.

“One year ago in this sanctuary, the world did not go to pieces, but a very treasured part of our building broke into pieces: our dear Dorcas window,” the Rev. Rob Mark said Sunday, in a restoration-themed sermon.

If the break-in was an emotional blow, the $65,000 restoration bill was an unbudgeted expense. Then a curious thing happened: News coverage of the vandalism brought attention to the church’s treasures, and its needs. The Windover Foundation sent $30,000 without being asked, supplementing insurance money and a host of smaller donations.

This fall, the church completed a three-year mission to gain federal recognition as a National Historic Landmark — rarer status than the National Register, conferred on fewer than 2,500 places. A few weeks ago, an anonymous donor gave $350,000, pushing annual fund-raising above $500,000.

“It was a thug breaking in for [little more than] a typewriter, and it has led to a blessing for the church,” said Lucy Williams of Roslindale, chairwoman of the building committee.

But there was still the matter of finding the glass. Rosa, whose studio specializes in conserving and restoring, could fabricate replacement glass that would seem good enough to many and that the church had accepted — but not Rosa. “It’s a once-in-a-lifetime situation,” he said. “We wanted to make it as perfect as humanly possible.”

He trekked to the American Glass Guild annual conference in Pittsburgh, but among 150 peers, none could replicate Tiffany’s drapery glass. Then a friend tipped him off to a New Jersey artist named Steven Stelz
who had revived the lost technique. Stelz provided raw sheets, and Rosa and his team toiled for months to hone and layer it — along with salvageable shards mended with epoxy — and recreate the leaded-glass window.

Following Mark’s sermon, the congregation rose from the pews and gathered beneath Dorcas, honoring Rosa and others and telling the window’s story, punctuated by a hymn and a standing ovation.

James, the window expert and a Medfield resident with an art history master’s, lingered to admire Dorcas, who looked better even than she did the last time she was intact, causing James to envision a time when the church might afford to restore all its windows.

“You go, girl!” church member Liz Vizza called on her way out. She meant James, but she could have been talking about Dorcas.

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